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Engine coolant staying cold?

PostPosted: Mon Feb 13, 2012 4:02 am
by bk_civiceg
My coolant temp gauge on the instrument cluster shows it being just above C. Sometimes it will creep up to normal operating temp range, but usually it's really really low. Do you think my temp sensor is bad, or is the thermostat stuck open?

When I've had the car on for quite a while and hit vtec, it immediately sends the Vtec CEL and vtec won't engage.

Any suggestions?

PostPosted: Mon Feb 13, 2012 4:18 am
by dbrooks
I personally think your temp sensor or gauge is bad.

If you think about it, radiant heat from the motor would heat the coolant up regardless. That's just theory though.

I'd start by swapping in a new cluster from a friend or something, then check the sensor, then swap your thermostat out if you have no luck.

Good luck!

PostPosted: Mon Feb 13, 2012 4:35 am
by TrailerTrash
dbrooks wrote:I personally think your temp sensor or gauge is bad.

If you think about it, radiant heat from the motor would heat the coolant up regardless. That's just theory though.

I'd start by swapping in a new cluster from a friend or something, then check the sensor, then swap your thermostat out if you have no luck.

Good luck!


id say this. could be the cluster but if nothing else, a new coolant sensor is like $20 and a thermostat is like $10

its pretty cold in here in pa this time of year and my coupe usually only gets warm enough to get the needle just over 1/3 of the way up. it NEVER gets up to the half way point(which I assume is operating temp). needless to say my heat is not heat its just not cold :lol: during the winter my fan literally doesnt come on. and my thermostat is fairly new and it was the same way with the old thermostat

PostPosted: Mon Feb 13, 2012 10:54 am
by EJ1_MK
Just remember this there are two temp sensors on the head. One is for the cluster and the other is for the ECU.


My bet is that the one for the cluster is going out. It will not throw a code. You should be able to test it with a volt meter. If you have a manual it should have the specs in it. check it and go on to the next problem.

PostPosted: Mon Feb 13, 2012 5:36 pm
by bk_civiceg
I'll check once the snow clears. We've got about three inches coming down right now.

Thanks!

PostPosted: Tue Feb 14, 2012 4:33 am
by TrailerTrash
EJ1_MK wrote:Just remember this there are two temp sensors on the head. One is for the cluster and the other is for the ECU.


My bet is that the one for the cluster is going out. It will not throw a code. You should be able to test it with a volt meter. If you have a manual it should have the specs in it. check it and go on to the next problem.


hmm... i was looking at this yesturday well at least i think i was looking at the right spot...is that why there are 2 wires coming out of the sensor?

EDIT: thats probably confusing.. but i cant find a picture of what i mean

PostPosted: Tue Feb 14, 2012 5:37 am
by Apexracing
My coupe always reaches normal operating temp regardless of the outside temp. Granted when its 20 or below it takes longer.

PostPosted: Tue Feb 14, 2012 6:58 am
by EJ1_MK
TrailerTrash wrote:
EJ1_MK wrote:Just remember this there are two temp sensors on the head. One is for the cluster and the other is for the ECU.


My bet is that the one for the cluster is going out. It will not throw a code. You should be able to test it with a volt meter. If you have a manual it should have the specs in it. check it and go on to the next problem.


hmm... i was looking at this yesturday well at least i think i was looking at the right spot...is that why there are 2 wires coming out of the sensor?

EDIT: thats probably confusing.. but i cant find a picture of what i mean


There is actually two different sensors, one is a two wire and the other is a one wire I believe. The two wire is the ecu temp sensor and the other is the cluster. both are usually close to the front of the head.

First pic you can barely see the other sensor its directly under the dizzy

Image

You can clearly see the ECU senor in this picture going into the head.

Image[/img]

PostPosted: Tue Feb 14, 2012 2:17 pm
by bks84
have you ever changed the thermostat since youve owned the car? if not do it.

did you check coolant level? if not, do it.

what CEL are you getting? if code 6, fix the wiring going to the sensor. code 6 is ECT, engine coolant temp, ecu needs to know the temp of the engine before vtec will engage since temp is a factor in vtec engagement.

PostPosted: Wed Feb 15, 2012 4:27 am
by TrailerTrash
EJ1_MK wrote:
TrailerTrash wrote:
EJ1_MK wrote:Just remember this there are two temp sensors on the head. One is for the cluster and the other is for the ECU.


My bet is that the one for the cluster is going out. It will not throw a code. You should be able to test it with a volt meter. If you have a manual it should have the specs in it. check it and go on to the next problem.


hmm... i was looking at this yesturday well at least i think i was looking at the right spot...is that why there are 2 wires coming out of the sensor?

EDIT: thats probably confusing.. but i cant find a picture of what i mean


There is actually two different sensors, one is a two wire and the other is a one wire I believe. The two wire is the ecu temp sensor and the other is the cluster. both are usually close to the front of the head.

First pic you can barely see the other sensor its directly under the dizzy

Image

You can clearly see the ECU senor in this picture going into the head.

Image[/img]


i see said the blind man :thumb:

PostPosted: Wed Feb 15, 2012 5:38 pm
by bk_civiceg
Only CEL that I get is Vtec Solenoid, and that rarely comes up. Changed fluid recently, I'll be changing the thermostat and testing the sensors.

PostPosted: Fri Feb 17, 2012 4:19 am
by TrailerTrash
bk_civiceg wrote:Only CEL that I get is Vtec Solenoid, and that rarely comes up. Changed fluid recently, I'll be changing the thermostat and testing the sensors.


my car did the same thing. it was the jerry rigged VTEC wires

im changing my ECT sensor this weekend... according to this pic
Image

the sending unit is the cluster one and the other one is for the ECU(the one ill be changing) correct?